Opening and closing device for well bore caliper



March 8, 1960 McMAHAN 2,927,377

OPENING AND CLOSING DEVICE FOR WELL BORE CALIPER Filed June 6, 1957 2 Sheets-Sheet 1 FIG. I. :2 FIG. 2. :2

INVENTOR. Durward B. McMahon,

MSK- [304-1- ATTORNEY.

March 8, 1960 D. B. MGMAHAN 2,927,377

OPENING AND CLOSING DEVICE FOR WELL BORE CALIPER Filed June 6, 1957 2 Sheets-Sheet 2 FIG.4.

b a 9 6 8 8 4 68 O n Y 6 7 5 5 B68 4 E R O N 7 77 O T 0 R 4! y o E T 7 C T M A liii 3. I- m B. A F m m w r U 0 8 2O 3 428 D 5 7 88 8 999 W. b b O 62 8 84 8O 0 M ma A 16 J i q 4 4 1 OPENING AND CLOSING DEVICE FOR WELL BORE CALIPER Durward B. McM'alian, Duncan, kla., assignor, by mesne assignments, to Welex, Inc., a corporation of Delaware Application June 6, 1957, Serial No. 664,032

4 Claims. (Cl. 33-178) This invention relates to an improved device for releasing and retracting the arms of an electrical well bore caliper.

The art of calipering well bores is well known. It is based on measuring the variations in diameter of a drilled well bore, means for calculating such variations and then recording the results. Caliper systems are operated either mechanically, electrically or hydraulicallly. In any system the arms of the caliper are maintained in a closed position, as the caliper is lowered into a well bore. Then the arms are released by some means, so that the arms will contact the walls of a well bore and move in response to the variations in the diameter of the well bore.

In many systems once the arms of the caliper are released, they cannot be retracted until the tool is removed from the bore hole.

Therefore, it is the object of this invention to provide a novel device which releases and retracts the arms of a conventional well bore caliper at the option of the operator.

The invention is adapted to be used with any type caliper that employs arms to contact the walls of a well bore. A specific adaptation is in connection with the electrical caliper disclosed in Patent No. 2,340,987 to Robidoux.

Other objects and advantages of the present invention will become apparent from the following description, when taken in connection with the accompanying drawings in which:

Figure 1 is a view in elevation of a caliper embodying the present invention and showing the parts in the position which they assume as the caliper is being lowered into a well bore;

Figure 2 is a view in elevation of the caliper of Figure 1, but showing the parts in the position they assume while the well bore is being calipered;

Figure 3 is a sectional view in elevation showing the detailed parts of the caliper of Figure 1 with the caliper arms in the position shown in Figure 2;

Figure 4 is a sectional view in elevation showing the detailed parts of the caliper of Figure 1;

Figure 5 is a detailed view of the valve mechanism of the caliper of Figure 1 showing the position of the various parts in the tripping position, i.e., in the position assumed by'the parts just prior to the position shown in Figure 3;

Figure 6 is a cross sectional view taken along the line 66 of Figure 3;

Figure 7 is a cross sectional view taken along the line 77 of Figure 4.

Referring to the drawings in detail, and first to Figures 1 and 2, a caliper tool is there shown as it is being lowered into a well bore 10 upon a single conductor cable 12. The cable may be of a known type commonly used in the oil fields for electric logging and which has a steel sheath. A coupling member 14 provides suitable nited States Patent electrical connections between the cable 12 and the various components of the caliper tool.

The caliper tool proper consists of a fluid sealed hous; ing 16, a plurality of caliper arms 18, a nose plug 20, connected to the housing 16 by support rods 22, and a pressure balance member 24. The nose plug 20 is provided with recesses 26 adapted to protect the caliper arms 18, as the tool is lowered into the well bore 10.

As shown in Figures 3 and 4 of the drawing, the fluid sealed housing 16 has disposed therein a plurality of elements of the present invention. At the top a fluid reservoir 28 is defined by the walls of the housing 16, a plate 30, and the case of the coupling member 14. To prevent fluid leakage past the plate 30, O-rings 32 are provided.

Mounted inside the reservoir 28, which is filled with a fluid, such as oil, is a conventional electric motor 34, which is adapted to receive electrical energy from a source at the surface by means of the single conductor cable 12 and the coupling member 14. The motor 34 drives a conventional hydraulic pump 36. The pump 36 is provided with a fluid inlet 38 and a fluid discharge conduit 40. The fluid inlet 38 is provided with a screen 42 which removes all foreign matter.

The plate 30 is provided with a check valve 44 which prevents fluid from the reservoir 28 passing into a fluid return conduit 46, but permits fluid to return to the reservoir 28 by means of the fluid return conduit 46. A fluid passage 40a is also provided in the plate 39 and is connected to the fluid discharge conduit 48 and a fluid discharge conduit 40b by any suitable means 48 and 48a.

A member 50, provided with a bore 52 and a spring seat 54, defines a chamber 56 with the plate 30 and the walls of the housing 16. The bore 52 is adapted to receive a hollow piston rod assembly 58. The chamber or cylinder 56 provides clearance for the upward movement of the piston rod 58.

The member 50 and a member 66, with the walls of housing 16, define an upper cylinder 62. The cylinder 62 contains air at atmospheric pressure. O-rings 64 pro vide seals for the member 50 and O-n'ngs 66 provide seals for the piston rod 58.

Fitted inside the cylinder 62 is a piston 68, which is firmly attached to the piston rod 58 by any suitable means such as 70. The piston 68 is sealed by O-rings 72. A spring seat 74 is provided at the top of the piston 68. Positioned between spring seats 54 and 74 is a spring 76. In the piston 68 is a cavity 78 adapted to contain a spring 80 and a plunger 82. The plunger 82 is provided with a resilient sealing seat 83.

The member 60 has a fluid passageway 84 which is connected to the fluid discharge conduit 40b by any suitable means such as 86. A check valve 88 is provided in the passageway 84 to prevent fluid from reversing into the conduit 40b. The member 69 is sealed by O-rings 90.

Fitted into the member 60 is a plug 92 having a fluid are connected together by an adjusting coupling 63. The

lower end of the conduit 59 of the piston rod section 58b communicates with the interior of the pressure balance member 24.

The bottom of the housing 16 is provided with a closure 100. A cylinder 182 is defined by the walls of the housing 1.6, the closure 1% and the member 60. A guide plate 194 is. rigidly mounted insidethe cylinder 102 by a means 106 which is firmly anchored to the closure 100. The guide plate 104 is provided with: openings for the passage of the piston rod 581) and follower rods 108 for the caliper armsrls', and serves as an upper seat for the springs 11% of the follower rods 188. Each of rods 108 has an integral abutting flange 111 which serves as a lower seat for its respective spring 110. Rods 108 extend through a plate or flange 112 and are forced by springs 110 into following support with cams 118 of caliper arms 18. Plate 112 is connected to piston rod 581).- When rod 58b is raised by piston 68, plate 112- engages the flanges 111' and lifts the rods 108. The closure 100 is sealed by O-rings 101. V p 7 Below the closure 10! a slotted plate 114 is provided which slides on the piston rod 58 by the aetion'of. a spring 115. Slots 116 are provided to receive cams 1189f the caliper arms 18. Fitted transversely in the cams 118 are pins 120, which are adapted toride on the surface ofi the plate 114 as the caliper arms 18 are rotated around fulcrum pins 122 which are mounted to the housing-16. Stops 113 are provided to limit the downward movement of the plate 114." j I Since the caliper arms '18 and the lower ends of the follower rods 108 are exposed to the pressures of in the well bore, it is necessary that thetool be pressure balanced. The cylinders 56 and 102, the conduit 59 of the piston rod assembly 58,- and; -the pressure balance member 24 are maintained full of a fluid preferably an oil.

Fluid communication is attained between the cylinders 56' and 102 through an equalizing port 61, shown in the coupling 63, and conduit 59., Fluid communication between the cylinders 56 and 102 may be alternately established by providing clearance aroundthe conduits 40b and 46 (not shown). H p

Shown in cylinder 102 are housings for conventional resistors or potentiometers 124, which are responsive to arms 18 will remain retracted until additional pressure is applied to the system by the pump 36. As shown in Figure 4 the system is held under the pressure applied above when the pump 36 is stopped. The check valve 88 prevents the fluid from reversing into the conduit 4%. Meanwhile the seat 83 offthe plunger 82 maintains the passageway 94 closed and thus prevents fluid from returning to the reservoir by way of the conduit 46. As the fluid enters the cylinder 62 and acts on the bottom of the piston 68, it also enters the recess 78 of the piston 68 and exerts a downward force on the plunger 82 tending to maintain the seat 83in sealing contact with the opening a of the passageway 94. This fluid pressure is greater than the force of the spring 80 which would tend to move the plunger 82 upwardly andthus'unseat the seat 83. As

shown in Figure 4, thespring 80 is not completely compressed as a clearance is shown between the piston 68 and the member 50. Thecaliper 18 will remain in the retracted position for several days under the conditions described above. 1

With the caliper arms 18 in the retracted position tool is then lowered into the well bore 10 to the desired depth; While lowering the tool to the bottom of the well bore '15} the nose plug 20 protects the caliper arms 18" from damage. g

To release the caliper arms 18; so thatthe well bore 10 maybe caliperedin the conventional manner, the

pump 36 is again operated by, .the motor 34; Additional fluid is pumped through the system and moves the piston 68 to the position shownin Figure 5' where the piston 68 just barely contacts the member 50. The spring" 80 corn presses fully. At full compression its force is suflicient to overcome that of the fluid actingonthe plunger 82. The plunger 82 moves upward and the seat 83 uncovers the passageway 94, thereby allowing the fluid to return to the reservoir 28 through the conduit 46. The spring 76 moves the piston 68 downwardly as the fluid is discharged 7 from the cylinder 62. The force exerted by the springs the movements of the caliper arms 18fo'r the purpose of 7 recording the diameter of the bore hole on equipment at the surface. a

An example of such a device used in connection with this invention is the aforementioned United States Patent Phi-2,340,987 to RobidouX. 7 V 3 An illustration of the operation and coaction of the elements of the invention is as follow "llheassembled tool of the invention before 'being flowcred into a well bore is in the positionshown in Figure 2 of the drawing with the caliper arms 18" extended or in thecalipering position.

7 in order to retract the caliper '18 so that the tool maybe lowered into a well bore 10, the conductor cable 12 of the surface equipment'is connected to 'thetool by means of the coupling member 'The electric motor 34' is started and operates the pump 36. Fluid in the reservoir 28 is picked up by the pump 36 through the fluid inlet 38. The fluid is pumped through the fluid dischargeconduit 40 into the fluid passage 4m, through the fluid discharge conduit 40b, past the check val W 88 and into'the bottom of the cylinder 62.

g 7 As shown in Figure the fluid under the pressure of the pump 36 acts on the-bottom of the ipiston268 forcing it upward and thereby compressing springs 76 and 80. a As the piston 68' moves upwardly, the piston rod assembly 58 also moves in the same direction. The plate 110 also .aids'in moving the piston168, as they act on the plate 112 which is firmlyattached t o-the section 585' of the piston rod assembly 58.. ,The follower rods 108 are pushed downwardly by the springs I10 and ride on the cams 118, which pushes the caliper arms out into the calipering position. The component parts assume the position shown in Figure 3. The .choke98 prevents a too rapid dischargeof the fluid."

The well bore 10 is then calipered man er- N. 7

Should it lee-desirable to retract the caliper arms 18 for any reason while the tool isinthe we'llbore .19, they may be retracted as described above. When the caliper arms 18 .reach the fully retracted positiong the tool is so calibrated that theactionof: the follower rods 108 on the mechanism of theresistors llfi will. record the known diameter of the toolon the surface equipment, showing that the arms are in the: fully retracted position, so that the pump may be stopped at: the proper time.

Although the invention has. been: described in terms of a specific embodiment, it should'he understood that this was by way of illustrationonly and that the invention isqnot limited thereto: Accordingly, modifica- IIZ -attached to the' piston rod section;. 58b moves the flanges Ill-upwardly and compresseswthe springs 110, causing the follower rods .108 to move upwardly. his

allows the caliper arms 18 to retract into the recesses 26 ot the no'seplug 20*. The spring 115' moves the slotted: plate 114 upwardly. The ,pins 120 of the cam 1'18ride on the surface of the plate 1 14 and hold the caliper arms 18in the position shown in Figure 4.

When the caliper a'rm's'18 are in the fully retracted position, the motor 34 and the pump 36 are stopped and the of the appended claims.

I' claim:

1. A device adapted for use with a toolif ormaliing acaliper log- 0f.- a well. bore; Comb mi Qfir a fluid sealed housing, a fluid reservoir in vvsaid housing, a

source-ofpower in said .rcservoir., a.pump operated by fluid return means connecting said rescryoir and' said pump, means to controlthe' directionnf flow of fluid in said fluid return means,;a cylinder belowsa'i'd' reservoir'in in the conventional having a vertical conduit, a spring in said cylinder, said spring adapted to react on the upper surface of said piston, a plunger and spring assembly in said piston, fluid conduit means in said housing, said fluid conduit means connecting said cylinder with said reservoir, a sealing means on said plunger adapted to control the opening and closing of said fluid conduit means, and means to pressure balance said housing.

2. in apparatus ror releasing and retracting elements of a well tool, the combination of a fluid sealed housing, a reservoir disposed within said housing, a pump disposed within said housing having an inlet in fluid communication with said reservoir, a cylinder disposed within said housing, a piston disposed within said cylnder, a piston rod for releasing and retracting said elements attached to said piston, a spring disposed within said cylinder for reacting on a first end of said piston, a first fluid conduit means disposed in said housing for providing fluid communication from an outlet of said pump into said cylinder at the second end of said piston, means to control direction of fiow in said first conduit means, a second conduit means disposed in said housing for providing fluid communication from said cylinder at the second end of said piston into said reservoir, means to control the direction of flow into said second conduit means, a spring and plunger assembly disposed Within said piston, sealing means disposed on said plunger, said plunger and sealing means closing said second conduit means when the second end of said piston is near its end of said cylinder and opening said second conduit means when the second end of said piston is moved by fluid pressure a preelected distance from said cylinder end, and means to pressure balance said housing.

3. An apparatus for releasing and retracting elements of a well tool, the combination of a fluid sealed housing, a reservoir disposed within said housing, a pump disposed within said housing having an inlet in fluid communication with said reservoir, a cylinder disposed within said housing, a piston disposed within said cylinder, a pisto'n rod for releasing and retracting said elements attached to said piston, a spring disposed within said cylinder for reacting on a first end of said piston, a first fluid conduit means disposed in said housing for providing fluid communication from an outlet of said pump into said cylinder at the second end of said piston, a second conduit means disposed in said housing for providing fluid communication from said cylinder at the second end of said piston into said reservoir, a spring and plunger assembly disposed within said piston, sealing means disposed on said plunger, said plunger and sealing means closing said second conduit means when the second end of said piston is near its end of said cylinder and opening said second conduit means when the second end of said piston is moved by fluid pressure a preselected distance from said cylinder end, and means to pressure balance said housing.

4. Apparatus for releasing and retracting elements of a well tool comprising, a fluid sealed housing, a reservoir disposed Within said housing, a pump disposed within said housing having an inlet in fluid communication with said reservoir, a cylinder disposed within said housing, a piston disposed within said cylinder, a piston rod for releasing and retracting said elements attached to said piston, a spring disposed within said cylinder for reacting on a first end of said piston, a first fluid conduit means disposed in said housing for providing fluid communication from an outlet of said pump into said cylinder at the second end of said piston, a second conduit means disposed in said housing for providing fluid communication from said cylinder at the second end of said piston into said reservoir, a spring and plunger assembly disposed within said piston, and sealing means disposed on said plunger, said plunger and sealing means closing said second conduit means when the second end of said piston is near its end of said cylinder and opening said second conduit means when the second end of said piston is moved a preselected distance from said cylinder end.

References Cited in the file of this patent UNITED STATES PATENTS 

